In case that a node constituting a communication system is capable of receiving a GPS signal, the node restores and generates a clock based on frequency synchronization and timing synchronization acquired through the GPS synchronization signal. Here, a master node denotes the node capable of receiving the GPS signal.
Alternatively, in case that a node constituting the communication system is not capable of receiving a GPS signal, the node restores and generates a clock based on frequency synchronization and timing synchronization acquired through synchronization information received from the master node. Here, a slave node denotes the node not capable of receiving the GPS signal.
The slave node acquires synchronization information from packets received from the master node. Thus, if a traffic load increases, there is a problem that the slave node suffers a phase jump as illustrated in FIG. 1 due to a transmission delay of the packets including the synchronization information.
FIG. 1 is a graph that illustrates a variation of a clock phase dependent on a traffic load in a communication system according to the conventional art.
As illustrated in FIG. 1, if a traffic load 100 increases suddenly, a slave node experiences the problem of a clock phase 110 jumping due to a transmission delay of packets that include synchronization information.
Another problem is that a phase jump or phase deviation which interferes with phase synchronization in the slave node occurs due to a phase difference that results from physical and temporal difference of a network path.